This invention relates to a refrigeration cycle apparatus. A refrigeration cycle apparatus generally comprises a compressor, condenser, electromagnetic valve, capillary tube acting as a decompressing device, evaporator and stop valve all arranged in series. The stop valve is connected to the compressor, thereby assuring a refrigeration cycle. The compressor causes a coolant to circulate through a refrigerating cycle by passing through the above-mentioned members in succession. The coolant is volatilized in the evaporator, and performs refrigeration by absorbing evaporation latent heat from the surrounding region. When the compressor is brought to rest, a signal is issued to close the electromagnetic valve. At this time, a coolant gas in the process of being compressed in the cylinder of the compressor flows back to the suction side of the compressor, that is, the side of the stop valve. However, the stop valve prevents the back-flowing coolant gas from running into the evaporator. Further, the electromagnetic valve which is closed at this time prevents a liquid coolant collected in the condenser from flowing into the evaporator. In other words, when the compressor is at rest, the high and low pressure sides of the evaporator are shut off by the stop valve and electromagnetic valve. As a result, the temperature of the evaporator increases only slightly when the compressor stops, thereby reducing loss of the refrigerating capacity of the refrigeration cycle apparatus when it is started again. The compressor substantially retains the gas pressure prevailing immediately before its stoppage. When started again, therefore, the internal pressure of the compressor quickly rises, thereby assuring the reduction of power consumption.
However, the conventional refrigeration cycle apparatus of the above-mentioned arrangement has the drawbacks as follows. Since the apparatus is necessary to provide an electromagnetic valve and stop valve, piping work is complicated. The electromagnetic valve is relatively expensive and an electric circuit has to be provided for the actuation of the electromagnetic valve. Therefore the refrigeration cycle apparatus is expensive. In addition, a relatively large power consumption is involved.